Researchers Identify Specific Gut Bacteria Linked to Faster and Slower Biological Aging

The bacteria living in our gut may influence how quickly our bodies age, with new research identifying specific microbes linked to faster and slower biological aging. A study suggests that differences in gut bacterial composition could provide important clues about aging and long-term health.

Published in the journal Scientific Reports, the study conducted by researchers at the University of Hawaiʻi at Mānoa investigated the relationship between the gut microbiome and biological aging.

The gut microbiome consists of trillions of microorganisms living in the digestive system. These microbes help regulate digestion, metabolism and immune function, and researchers are increasingly exploring their possible role in aging.

The study involved 123 adults across different age groups. Researchers analysed stool samples to identify gut bacteria and examined blood samples for molecular markers associated with biological aging.

Unlike chronological age, which measures the number of years a person has lived, biological aging reflects the rate at which aging-related changes occur within the body.

Researchers used a blood-based biomarker called DunedinPACE to estimate how quickly participants were aging biologically.

The findings revealed that differences in gut bacterial communities accounted for approximately 15% of the variation in biological aging rates.

Importantly, researchers identified specific bacteria associated with different aging patterns.

Bifidobacterium adolescentis showed one of the strongest associations with slower biological aging, while Succinivibrio dextrinosolvens was linked to faster aging.

Researchers suggested that gut bacteria may reflect biological processes influenced by diet, lifestyle, and environmental exposures.

However, the study was observational and involved a relatively small number of participants, meaning it could not establish whether particular bacteria directly accelerate or slow aging.

Further research is needed to determine whether changing gut microbial composition through diet or other interventions can influence biological aging.

The findings highlight the potential of gut microbiome research to improve understanding of healthy aging and support future personalised health strategies.

REFERENCE: Braden P. Kunihiro, Brennan Y. Yamamoto, Ruben Juarez, Alika K. Maunakea. Gut microbiome signatures associate with DNA methylation-based biological aging. Scientific Reports, 2026; 16 (1) DOI: 10.1038/s41598-026-52974-x